/// <summary>
/// Read SSH.com SSH2 private key parameters.
/// </summary>
/// <param name="passphrase">passphrase for decrypt the key file</param>
/// <param name="keyPair">key pair</param>
/// <param name="comment">comment or empty if it didn't exist</param>
/// <exception cref="SSHException">failed to parse</exception>
public void Load(string passphrase, out KeyPair keyPair, out string comment)
{
if (keyFile == null)
{
throw new SSHException("A key file is not loaded yet");
}
String base64Text;
using (StreamReader sreader = GetStreamReader()) {
string line = sreader.ReadLine();
if (line == null || line != PrivateKeyFileHeader.SSH2_SSHCOM_HEADER)
{
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (missing header)");
}
StringBuilder buf = new StringBuilder();
comment = String.Empty;
while (true)
{
line = sreader.ReadLine();
if (line == null)
{
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected eof)");
}
if (line == PrivateKeyFileHeader.SSH2_SSHCOM_FOOTER)
{
break;
}
if (line.IndexOf(':') >= 0)
{
if (line.StartsWith("Comment: "))
{
comment = line.Substring("Comment: ".Length);
}
}
else if (line[line.Length - 1] == '\\')
{
buf.Append(line, 0, line.Length - 1);
}
else
{
buf.Append(line);
}
}
base64Text = buf.ToString();
}
byte[] keydata = Base64.Decode(Encoding.ASCII.GetBytes(base64Text));
//Debug.WriteLine(DebugUtil.DumpByteArray(keydata));
SSH2DataReader reader = new SSH2DataReader(keydata);
int magic = reader.ReadInt32();
if (magic != MAGIC)
{
throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (magic code unmatched)");
}
int privateKeyLen = reader.ReadInt32();
string type = Encoding.ASCII.GetString(reader.ReadString());
string ciphername = Encoding.ASCII.GetString(reader.ReadString());
int bufLen = reader.ReadInt32();
if (ciphername != "none")
{
CipherAlgorithm algo = CipherFactory.SSH2NameToAlgorithm(ciphername);
byte[] key = SSH2UserAuthKey.PassphraseToKey(passphrase, CipherFactory.GetKeySize(algo));
Cipher c = CipherFactory.CreateCipher(SSHProtocol.SSH2, algo, key);
byte[] tmp = new Byte[reader.Image.Length - reader.Offset];
c.Decrypt(reader.Image, reader.Offset, reader.Image.Length - reader.Offset, tmp, 0);
reader = new SSH2DataReader(tmp);
}
int parmLen = reader.ReadInt32();
if (parmLen < 0 || parmLen > reader.Rest)
{
throw new SSHException(Strings.GetString("WrongPassphrase"));
}
if (type.IndexOf("if-modn") != -1)
{
//mindterm mistaken this order of BigIntegers
BigInteger e = reader.ReadBigIntWithBits();
BigInteger d = reader.ReadBigIntWithBits();
BigInteger n = reader.ReadBigIntWithBits();
BigInteger u = reader.ReadBigIntWithBits();
BigInteger p = reader.ReadBigIntWithBits();
BigInteger q = reader.ReadBigIntWithBits();
keyPair = new RSAKeyPair(e, d, n, u, p, q);
}
else if (type.IndexOf("dl-modp") != -1)
{
if (reader.ReadInt32() != 0)
{
throw new SSHException(Strings.GetString("UnsupportedPrivateKeyFormat")
+ " (" + Strings.GetString("Reason_UnsupportedDSAKeyFormat") + ")");
}
BigInteger p = reader.ReadBigIntWithBits();
BigInteger g = reader.ReadBigIntWithBits();
BigInteger q = reader.ReadBigIntWithBits();
BigInteger y = reader.ReadBigIntWithBits();
BigInteger x = reader.ReadBigIntWithBits();
keyPair = new DSAKeyPair(p, g, q, y, x);
}
else
{
throw new SSHException(Strings.GetString("UnsupportedAuthenticationMethod"));
}
}
